1. Field of the Invention
The present disclosure relates to an induction cooking device for home or commercial use. In particular, the present disclosure relates to the structure in the induction cooking device for attaching a top plate on which an object to be heated is placed.
2. Description of the Related Art
Induction cooking devices are highly efficient in terms of converting input energy into heat. Moreover, it is easy to control the cooking temperature with induction cooking devices. Further, induction cooking devices produce little radiant heat, are safe, and are easy to clean. Accordingly, induction cooking devices have more advantages than other cooking devices. As such, induction cooking devices are used in many places, and come in a variety of types suitable for different places, such as built-in devices, stand-alone devices, and table-top devices. Examples of commercial induction cooking devices include counter-top devices that are placed on a kitchen counter, and recessed devices that are built into a kitchen counter. These induction cooking devices are large and designed to withstand use over a long span of time.
Typically, in induction cooking devices, the distance between the internal heating coil unit and the top plate is maintained by the heating coil being pressed against the bottom surface of the top plate with a spring. With induction cooking devices, when the distance between cookware (object to be heated) placed on the top plate, and the heating coil changes, the high-frequency voltage and high-frequency current generated in the inverter circuit that supplies high-frequency current to the heating coil changes, and as a result, the product cannot perform as designed. Moreover, the distance between the cookware and the heating coil is preferably as short as possible from the standpoint of heating efficiency. Therefore, minimizing the distance between the top plate on which the cookware is to be placed and the heating coil and maintaining that distance at all times is important for ensuring the performance of the induction cooking device.
Examples of top plates for placing the object to be heated used in induction cooking devices include glass plates and ceramic plates that are magnetically permeable and have a low rate of heat transfer. The top plate is fixed to the main body housing frame via an adhesive. A configuration in which caulk fills the gap between the top plate and the housing frame around the outer perimeter of the top plate has been proposed (for example, see Japanese Unexamined Utility Model (Registration) Application Publication No. S62-136091 and Japanese Unexamined Patent Application Publication No. 2006-147303).